To meet customer requirements, in addition to being slim and light, “wireless” has become a trend for the development of information appliances. “Wireless” means that information transmission and power supply have to adopt a new approach. As a result, wireless communication technology and electric charging technique have rapid innovation.
Take electric charging technique for instance. To increase charge capacity at a smaller size is a natural focus. However, to maintain long use time also is important. To meet this end, power saving technique has to be developed to increase power supply time of the charging elements. The design concept of power saving technique mainly aims to stop some power-hungry elements such as CPU and MCU (Microprocessor Control Unit) from operation when not in use, and start operation when in use so that electric power during standby mood may be saved. Meanwhile, the information appliances powered by charged battery can be used for a longer duration with the same amount of electricity.
Take the wireless mouse for example. In the present design, electric output continues even in the sleeping mode. This is because the wake-up device has to be maintained in an operation mode so that environmental changes resulting from user's operation action in the next cycle may be detected to activate the wireless mouse. Such a design is the main stream in the present market. Different techniques have been developed for switching the sleeping mode. For instance, U.S. Pat. No. 5,854,621 adopts a timer to wake up detection automatically. A wake up signal is output according to a selected time interval, and checks whether users are proceeding operations. Japan patent Nos. 11-224158 and 11-242560 employ a vibration detection mechanism to enable a wireless mouse to generate vibration and wake up signals. Japan patent, No. 10-124250, employs static charge to perform detection. All these designs have a common problem, i.e. the wake up device continuously consumes electric power in the sleeping mode. Once the standby mood time is extended for a prolonged duration, the batteries are empty and have to be recharged. Moreover, these designs, because of focusing on convenience, often overlook many environmental parameters. Switching of the sleeping mode usually is accomplished through a sensor approach. Mistaken wake up actions often occurs. Moreover, electric power is consumed excessively during the standby mood period.
A wireless mouse with a built-in charge battery, though it can compensate a lack of electricity, charges in the sleeping mode while the wake-up device consumes electric power. As a result, the battery cannot be fully charged. In addition, the battery is under a charging condition for a long period. It has a negative effect to battery service life. Even for machine models that do not have a sleeping mode, charging for a long period in the power-on mood also damages the service life of the battery.